Brian Madge Alice class Hunslet part 7 - turning a new chimney.

I've turned myself a new chimney for my Brian Madge small quarry Hunslet. There's nothing wrong with the casting supplied with the kit, but as I have a lathe and enjoy making things on it I decided that turning up a chimney would be an enjoyable way to spend a morning. Its also a way of adding a personal touch to the kit, and a turned chimney always looks better than even the finest casting.

The first job, as always, was to prepare a simple 'fag packet' sketch, dimensioned in millimetres, from the drawing in Cliff Thomas' excellent 'Quarry Hunslets of North Wales'.

This time I decided to take a different approach to forming the bottom flange, so I hand filed the end of a length of 5mm dia. bar to suit the smokebox, not too difficult as long as care is taken and the hand remains steady;

Of course this would be harder work if making the chimney for a larger loco, probably requiring fly-cutting.

The actual turning of the chimney was basically the same as for the Waril type, apart from leaving the bottom of the flange solid and the shape of the top cap, which is convex above the lip and concave below. The top of the lip was formed with a file, and the lower part formed using a round-nosed tool (as was the bottom flange). The bottom was also drilled with a 1mm drill so that it could be pinned to the smokebox. Here it is ready for the next operation;

Note the flat sections seen at the top and bottom of the smokebox flange, these needed blending in with a round needle file. So the turning was now removed from the chuck before parting off to make holding the chimney easier when filing.

The filing itself was just more steady work with a fine needle file and wet+dry. I wrapped a piece of masking tape around the parallel section to protect it from stray file marks, and checked the work regularly with a magnifying glass;

Once I was happy with the shape the chimney could be re-chucked in the lathe and parted off. The next job was to drill it out from the top. To do this I held it in a split mandrel (7mm dia. brass, skimmed over the top and drilled to suit the centre section of the chimney, then cut in half down the centre with a razor saw and parted off) and drilled it out to 1.8mm dia., 7mm deep;

And here's the end result, along with the supplied whitemetal casting and the split collet;

And placed on the loco;

Those that know a little of the history of my model will be interested to learn that the damage inflicted upon it (cab backsheet snapped off!) has now been repaired.

Paul.